Electrical apparatus



July 20, 1937. w. c. BAUMANN ELECTRICAL APPARATUS Original Filed Nov.25, 1932 Patented July 20,. 1937 UNITED STATES.

PATENT OFFICE Application November 25, 1932, Serial a... 644,156 RenewedJune 3, 1935 16 Claim.

This invention relates to electrical apparatus and more particularly toan electrical transformer apparatus productive of various secondaryvoltages.

One object of the invention is the provision of an electricaltransformer apparatus having relatively movable primary and secondarywindings and embodying core elements so arranged as to produce asubstantially constant flux path lo for all positions of the movablewinding.

Another object of the invention is the provision of a transformerapparatus having relatively movable secondary and primary windingsarranged on a closed core ring and an inner movable core cylinder bothof which are uniformly slotted for the reception of the windings.

Another object of the invention is the provision of a variable voltagetransformer of the character above mentioned, having a plurality ofsecondary windings provided on the stationary core element and arrangedfor individual connection to different loads so that as the primarywinding is rotated slowly there will be a variation of phase displacedsecondary voltages which gradually increase and decrease to maximum andminimum values.

Another object of the invention is the provision of a motor drivenmovable core transformer having a plurality of individual secondarywindings connected to differently colored lights so as to provide agradually changing color effect of illumination as the movable core isrotated.

Another object of the invention is the provision of a combination of amovable coil transformer as above set forth and having a number ofmovable secondary windings all cooperating with the same primarywinding, the secondary windings being connected to the lamps of achasing border sign so that the lamps will be successively lighted tocreate an apparent movement of an illuminated band in the border.

Other objects and advantages of the invention will be apparent from thefollowing description, the appended claims and the accompanying drawing,in which- Fig. 1 is a side elevation, partly in section, of anelectrical apparatus embodying the present invention;

Fig. 2 is a diagrammatic view of the winding relationship of theapparatus shown in Fig. 1;

Fig. 3 is a detailed end view of a portion of the fixed and movable coreelements;

Fig. 4 is an end view, partly broken away, of

(Cl. l'11119) a modified form of an electrical transformer having asingle movable secondary coil; and

Fig. 5 is a diagrammatic showing of the electrical connections andwindings of a transformer and lamp arrangement productive of a chasing 5border effect.

Referring more particularly to the drawing by reference numerals. andfirst with respect to Figs. 1 to 3, III designates generally the housingor casing of a movable coil transformer which has been generallydesignated by the numeral II. This transformer embodies a primarywinding adapted for connection across an alternating current supply suchas an ordinary 110 volt, cycle power line. Inductively related with re-15 spect to the primary winding, in the example of the invention shownin Fig. 1, are three secondary windings, although it will be understoodthat the transformer may be arranged to have any desired number of suchwindings. The ar- 20 rangement is preferably such that the secondarywinding is fixed, while the primary winding is rotatably movable withinthe secondary.

As shown, the primary winding I2 is arranged in the outer slots I3 of asubstantially cylindrical movable core l4, being wound around the corefrom end to end in several of the slots so as to produce flux linesdiametrically across the core I. The core may be constructed of a.number of fiat iron disks stacked together and suitably attached to acentral supporting shaft IS. The fixed core element is also preferablybuilt up of a stack of iron laminations or plates of ring-like form,providing an outer fixed closed core ring I! which surrounds the movablecore.

The outer core ring I! is provided with inside slots l8 which areregularly or uniformly arranged completely around the ring. Thesecondary windings are provided in the slots l8, and, as shown in Fig.2, there are three secondary windings I9, 20 and 2|, each of which isquite independent of the other but all of which are inductively relatedwith respect to the primary winding l2. The secondary winding 2| forexample embodies conductors or wires extending longitudinally orparallel to the axis of the core I 4 in the slots I8 of the fixed coreelement. The slots in which the secondary winding 2| is contained arediametrically opposite and the ends of the conductors of this windingare interconnected at the ends of the core element I! so that thewinding 2| is inductively related with respect to the primary winding.When the windings are in the relative positions shown in Fig. 3, amaximum voltage will be generated in" the secondary winding as thecurrent flows through the primary.

secondary windings i9 and 20 are similar to the winding 2i, but thethree windings are anguiarly displaced with respect to one another. thegeometric plane of one secondary winding being l20 away from the planesof the other two windings. If four secondary windings were employedthese windings would be displaced angularly 90 apart.

The air gap between the fixed and movable core elements is only a smallfractional part of an inch, and this air gap is constant regardless ofthe position of the primary or movable coil since both core elements areuniformly slotted throughout their entire circumferential extent. Thenumber of slots in the movable core is preferably substantially lessthan the number in the fixed core, and the ends of the slots are ofreduced size as shown in Fig. 3 so that the flux path will bepractically constant at all times in order that the primary winding willhave a very low exciting consumption. This allows a constant connectionto the supply line through the slip rings 23 to which the ends of theprimary windings extend.

Mounted on a support 24, which is common to the transformer housing I0,is an electric motor 25 connected by a suitable coupling 28 to a drivingpinion 21 rotatably mounted in the end cap or plate 28 of thetransformer housing. This pinion meshes with a gear 29 which is fixed toa pinion 30. Pinion 30 meshes with gear 3i fixed on the core supportingshaft l6. When the motor is energized it will be apparent that the coreof the transformer will be driven slowly through the speed reductiongearing just referred to. As the primary winding and its supporting coreis constantly rotated, the voltage across the ends of the secondarywindings i9, 20 and 2| will rise from a zero value to a maximum valuedependent on the ratio of turns and then fall again gradually, thevoltages of the three windings being displaced as to phase so that whenthe voltage of one winding is increasing, that of another is decreasingdue to the change in the inductive relationship of the primary withrespect to the secondaries.

The secondary windings of the movable coil transformer may be connectedto any desired loads. In accordance with one desirable arrangement, thethree secondary windings may be connected to differently colored lightsto provide a gradually changing color effect of illumination as themovable core is rotated. Thus the winding I9 may be connected to one orto a series of lamps 30 provided with light filters of any suitablecharacter to produce a red light for example. Secondary winding 20 isconnected to lights 3i productive of a different color such as green,and winding 2| may be connected to blue lights 32. Lights 30, 3i and 32may be used collectively for the illumination of a display. For examplethey may all be arranged to illuminate a common area of a building orother object. It will now be apparent that as the movable primary isslowly rotated the color effect of the illuminated area will graduallychange from one color to another, the change being a smooth variationwhich merges one predominating color into another as the lamps 30, 3|and 32 successively reach their maximum state of intensity. Lamps ofadditional colors in any desired number may also be employed andadditional windings provided on the fixed core element. The

several connections of the several secondary windings are readily madewithout constantly making or breaking electrical connections, since thesecondary windings are all fixed. As there is a single primary windingon the movable core element the supply of current to the movable memberis readily eilected by the simple slip ring arrangement previouslymentioned.

Fig. 5 shows the electrical connections of a slightly modified form ofthe invention, in which there are five secondary windings on the fixedcore element, arranged equal mechanical degrees apart and allinductively related to the movable coil 30, the arrangement of the fixedand movable core elements and of the windings and other parts beingsimilar to the construction shown in Fig. 1 except that the secondarywindings are now five in number instead of three, although of course anyother number of secondary windings could be employed. The secondarywinding designated 21 is connected to lamps 31a. The secondary windingll is connected to lamps "a, and in a similar manner the windings ll, Iand ii are connected to lamps "a, a and lid. These various lamps arearranged in a series, as shown in this figure, to provide a chasingborder effect of an illuminated sign, each sixth lamp beinginterconnected so that there will be a total of five circuits supplyingany desired number of lamps in the light border. The lamps may be of auniform white or other color, or the various lamps may be so arrangedthat all of the lamps 31a produce a certain color while the lamps 30a.produce another color. each of the lamps of one circuit beingdifferently colored or diiferently shaded in a common color so that theoverall color eilect of the chasing border will changeas the lamps of acircuit are gradually brought up to their maximum state of illuminationand as the different circuits are successively brought to a. zerovoltage. The driving motor which is connected to the movable primarywinding and its supporting core may constantly rotate these parts at aspeed of the order of SI revolutions per minute to produce an apparentmovement of a path of light along the sign and cause the lamps to beenergized and deenergized in a gradual manner.

In Fig. 4 an electrical transformer is shown having a movable coreelement provided with a single primary winding II. A single secondarywinding 52 is provided on the fixed core element 53, the arrangement ofthe windings and of the cores being similar to the arrangement of theseparts shown in Fig. 1, except that only one winding-is now provided ,onthe fixed core element. Such an arrangement is particularly desirablefor electrical welding. The primary winding Il may be supplied throughsimple rings from a 110 alternating current source, and the secondarywinding 52, of comparatively few turns, may be arranged for the supplyof low voltage current suitable for electrical welding operations. Thecore 50 is moved about its longitudinal axis by means of a suitablecontrol handle 55. Normally the parts are in the position shown in Fig.4, the primary winding being connected to the supply source and theinductive ei'lect on the secondary winding being zero. The secondarywinding is connected across parts to be welded together and then thehandle 55 is rotated a desired amount and at a suitable speed so as togradually raise the voltage from a zero amount to the amount requiredfor the weld. When the handle 55 is moved through the maximum weldingcurrent flows through the secondary and through the weld. The handle 55may be moved less than and then stopped for the desired welding intervalwhere less than the maximum obtainable voltage of the transformer isrequired for the welding operation. A tapered voltage is thereforesupplied to the welding electrodes which creates a tapered heat betweenthe two metals being welded and prevents flashing or fusing of themetals, as there is no instantaneous rush of current when contactors areclosed. The comparatively gradual increase in heat causes the meltingpoint of the metals to be welded to be reached without splatter-ing themetal so that pressure of the electrodes on the metal insures a perfectweld. Moreover the arrangement is such that when the weld is completedthe primary may be maintained energized, as a comparatively smallenergizing current is required for the transformer due to the fact thatthere is always a uniform large amount of iron in the transformersmagnetic flux path.

' While the forms of apparatus herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparatus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

l. A variable multi-voltage voltage transformer of the characterdescribed comprising an outer fixed closed core ring having insideslots, an inner movable core, a primary winding on the movable coreadapted for independent connection across an alternating current supplyand providing for generation of a magnetic fiux diametrically across thering, and a plurality of independent secondary windings each havingdiametrically opposite longitudinally extending conductors provided inthe slots of the ring and interconnected by end conductors, saidlongitudinally extending conductors of one secondary winding beingspaced radially of the corresponding conductors of the other secondarywindings about said ring, the end conductors of the several secondarywindings overlapping each other, and means to move the inner core aboutits axis to vary the voltages in the secondary windings.

2. A variable multi-voltage voltage transformer of the characterdescribed comprising an outer fixed closed core ring, an inner movablecore, a primary winding adapted for connection across an alternatingcurrent supply and providing for generation of a magnetic fiuxdiametrically across the ring, and a plurality of secondary windingselectrically independent from said primary winding and adapted forconnection to separate loads independent of said alternating currentsupply, each of said windings having diametrically oppositelongitudinally extending conductors regularly spaced from the othersthrough the complete circle of the ring and interconnected by overlappedend conductors, and means to move the inner core about its axis tosimultaneously vary the voltages induced in said secondary windings.

3. A variable multi-voltage voltage transformer of the characterdescribed comprising an outer fixed closed core ring, an inner movablecore, a plurality of independent fixed secondary windings provided onsaid ring and adapted for connection to separate loads, a movableprimary winding on the movable core, electrically independent from saidsecondary windings and inductively related with respect to the secondarywinding and adapted for connection across an alternating current supply,said ring and inner core providing a uniform flux path in all positionsof adjustment of the inner core, and means for moving said inner core onits axis to vary the voltage across the secondary windings.

4. An electrical apparatus of the character described comprising anouter fixed closed slotted core ring, an inner movable core cylinderhaving outside slots, a movable primary winding adapted for connectionacross an alternating current supply and provided in the slots of saidcylinder to produce magnetic flux diametrically of the cylinder, meansfor continuously rotating said cylinder on its axis, and a plurality ofindividual secondary windings on said ring electrically separate fromsaid primary windings and electrical- 1y separate from one another andadapted for separate connection to independent loads, said secondarywindings being angularly arranged with relation to one another on saidring.

5. An electrical apparatus of the character described comprising anouter fixed closed slotted core ring, an inner movable core cylinderhaving outside slots, the slots being uniformly spaced on the ring andon the cylinder to provide a substantially uniform flux path in allpositions of adjustment of the cylinder, a movable primary windingadapted for connection across an alternating current supply and providedin the slots of said cylinder to produce magnetic flux diametrically ofthe cylinder, means for continu ously rotating said cylinder on itsaxis, and a plurality of individual secondary windings on said ring andadapted for separate connection to loads, said secondary windings beingangularly arranged with relation to one another on said ring.

6. A variable voltage transformer of the character described comprisingan outer fixed core and a rotatable core therein, said fixed and movablecores providing a substantial uniform flux path in all positions of thecylinder, a primary winding on the movable core providing a fiuxdirection in a predetermined diametrical direction, and a plurality ofindividual secondary windings on said fixed core spaced regular angulardistances apart thereon and adapted for connections to individual loads,said secondary windings being electrically separate from said primarywinding and electrically separate from each other and means forcontinuously rotating said movable core at a slow speed.

'7. A variable voltage transformer of the character described comprisingan outer fixed core and a rotatable core therein, said fixed and movablecores having annularly spaced inside and outside slots respectively inwhich the secondary and primary windings are respectively arranged sothat a constant flux path is provided for all positions of the cylinder,a primary winding on the movable core providing a flux direction in apredetermined diametrical direction, and a plurality of individualsecondary windings electrically separate from said prim-arywinding andelectrically separate from each other and provided on said fixed corespaced regular angular distances apart and adapted for connections toindividual loads, and means for continuously rotating said movable coreat a slow speed.

8. An electrical apparatus of the character described comprising anouter fixed closed core ring having inside slots, an inner movable corecylinder'having outside slots, a primary winding adapted or connectionacross an alternating curiy and provided in the slots of said cyladarranged for the generation oi magnetic flux diametrically of thecylinder,- and a plurality or individual secondary windings eachinductively related with respect to the primary winding and angularlyspaced on said ring, said secondary windings being electrically separatefrom said primary winding and electrically separate from each other,each secondary winding having diametrically opposite longitudinallyextending conductors in the ring slots interconnected by end conductors,and means for continuously rotating said cylinder to provide phasedisplaced voltages which gradually rise and fall in the secondarywindings.

9. A variable voltage transformer comprising a primary winding and aplurality of inductively related secondary windings, said windings beingelectrically independent of one another relatively movable core elementssupporting said windings and so arranged as to produce a. substantiallyconstant flux path for all positions of the movable winding, meansconnecting the primary winding to an alternating current supply, andmeans for connecting each secondary winding to a separate loadindependent of electrical connection with said primary winding and itscurrent supply.

10. A variable voltage transformer comprising,

primary winding and a plurality of secondary windings electricallyindependent of one another and adapted for separate load connection,relatively movable closed core elements supporting -the respectivewindings and arranged to provide a substantially constant flux path forall positions of the movable winding, means connecting the primary to analternating current supply, and means for separately connecting theseveral secondary windings to their respective load connectionsindependent of electrical connection with said primary winding and itscurrent supply and in inductive relation with said primary whereby theprogressive relative movement of one core effects in the secondaries avariation of phase displaced secondary voltages increasing anddecreasing to maximum and minimum values.

11. A variable voltage transformer comprising a single primary windingand a plurality of second-aiy windings, concentric relatively movableclosed core elements supporting the primary winding and the group ofsecondary windings respectively and having between them a constant andminimized air gap, said windings being inductively related andelectrically independent, means connecting the primary winding to asource of alternating current supply, means connecting each secondarywinding to a. separate load and means to effect relative movementbetween the cores for effecting progressive variation in secondaryvoltage between zero and maximum values.

12. An electrical apparatus of the character described comprising anouter fixed closed core ring having a plurality of secondary windingsangularly spaced apart thereon, differently colored lamps one connectedacross each of said secondary windings, an inner core and a primarywinding on said inner core inductively related to and electricallyindependent of said secondary windlngs to provide gradually increasingand decreasing voltages in the secondary windings relatively displacedas to phase, said primary winding being adapted for connection across'an alternating current supply, and means for slowly rotating said innercore.

13. An electrical apparatus of the character described comprising anouter fixed closed core ring having a plurality of secondary windingsangularly spaced apart thereon, diflerently colored lamps one connectedacross each of said secondary windings, an inner core, and a primarywinding on said inner core electrically independent of and inductivelyrelated to said secondary windings to provide gradually increasing anddecreasing volt-ages in the secondary windings relatively displaced asto phase, said primary winding being adapted for connection across analternating current supply, an electric motor, and a speed reducinggearing between said motor and said cylinder for slowly operating saidcylinder in a continuous manner.

14. An electrical apparatus of the character described comprising arotatable core and an associated fixed closed core, a primary winding onthe rotatable core adapted for connection across an alternating currentsource, and a plurality of in: dividual secondary windings inductivelyrelated to the primary winding and angularly spaced apart on the fixedcore, a driving motor for rotating said movable core, and differentlycolored lights connected to said secondary windings and providinggradually changing color effects of 11- lumination as the movable coreis rotated.

current supply to'produce magnetic flux diametricallyof its core, theother of said windings constituting secondary winding independentlyconnectible to a load and means to effect relative rotation of saidcores and associated windings for impressing voltages varying from zerovoltage to maximum voltage on the load while said primary windingremains constantly energized.

16. In a device of the class described the combination of a plurality ofindependent lamp circuits including different colored lamps, a closedring. transformer core, a concentric relatively movable transformer coreproviding between itself and the ring core a constant and minimized airgap, a plurality of secondary windings in angularly related andoverlapping relation about the ring core electrically independent ofeach other and electrically connected respectively to the several lampcircuits and a primary winding on the movable core for connection to asource of alternating current supply whereby progressive relativemovement of said cores effects progressive variation in secondaryvoltage in said secondary windings and associated lamp circuits fromzero to maximum values for effecting progressive variation in intensityof color light value in each of said circuits whereby changing totalcolor light values are attained.

WILLIAM C. BAUMANN.

CERTIFICATE OF CORRECTION.

Patent No. 2,087,636. v July 20. 1937.

WILLIAM C. BAUMANN.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 3,second column. line 18, claim 4, for "windings" read winding; and thatthe said Letters Patent should be read with this correction therein thatthe same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of Gotober, A0 D. i937.

Henry Van Arsdaie (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORREC'IIOIi.

Patent No. 2.087.636 Jul 20. 1937.

WILLIAM C. BAUMANN.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 3;second column, line 18, claim 4, for "windings" read winding; and thatthe said Letters Patent should be read with this correction therein thatthe same may conform to the record of the case in the Patent Office.

'Signed and sealed'this 5th day of October, A. 0. 937.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

